Epoxysuccinic acid derivatives

ABSTRACT

An epoxysuccinic acid derivative of the formula ##STR1## wherein R 1  is hydrogen, alkali metal, alkyl having 1-2 carbon atoms, cycloalkyl having 5-6 carbon atoms or benzyl, R 2  is alkyl having 3-4 carbon atoms or benzyl, R 3  is hydrogen or methyl, and R 4  is alkyl having 1-10 carbon atoms, phenyl, benzyl, phenethyl or cycloalkyl having 3-6 carbon atoms or R 3  and R 4  taken together with the nitrogen atom to which they are attached form a 5-6 membered heterocyclic ring, or said heterocyclic ring substituted with a protected carboxy.

BACKGROUND

The prior art discloses E-64 (U.S. Pat. No. 3,911,111), itsintermediates [Chemical Abstracts, 87, 202108y (1977), ibid., 87, 85238c(1977), ibid., 87, 202125b (1977), ibid., 87, 68128z (1977)], andepoxysuccinic acid derivatives of German Patent Application Laying OpenNo. P 28 09 036 and Chemical Abstracts, 87, 68129a (1977) prepared byseveral of the present inventors.

The compounds of the present invention are distinguished from the priorart compounds by inhibitory activity to calcium-activated neutralthiolprotease (hereafter abbreviated as CANP) which exists in excess inmuscle of muscular dystrophy mammals, and good absorption and bydistribution in tissues after administration to mammals withoutacceleration of vascular permeability.

DESCRIPTION AND PREFERRED EMBODIMENTS

The present invention relates to a novel epoxysuccinic acid compound ofthe formula ##STR2## wherein R¹ is hydrogen, alkali metal, alkyl having1-2 carbon atoms, cycloalkyl having 5-6 carbon atoms or benzyl,

R² is alkyl having 3-4 carbon atoms or benzyl,

R³ is hydrogen or methyl, and

R⁴ is alkyl having 1-10 carbon atoms, phenyl, benzyl, phenethyl,cycloalkyl having 3-6 carbon atoms or a group of the formula ##STR3##wherein R⁵ is hydrogen, alkyl having 1-4 carbon atoms or said alkylsubstituted with hydroxy, methylmercapto, phenyl, hydroxyphenyl,indolyl, an optionally protected carboxy, an optionally protected aminoor an optionally protected guanidino, and

R⁶ is hydroxy, alkalimetaloxy, alkoxy having 1-2 carbon atoms,benzyloxy, amino or dimethylamino, or

R³ and R⁴ taken together with the nitrogen atom to which they areattached form a 5-6 membered heterocyclic ring, or said heterocyclicring substituted with a protected carboxyl.

In the present specification and claims, unless otherwise noted, theterm "alkyl" refers to both straight and branched chain alkyl groups,and the epoxysuccinic acid derivatives are trans isomers, namely, twocarbonyl groups on the oxirane ring are in the trans configuration.

With regard to the compounds of the present invention, the protectinggroups in the protected carboxy, amino and guanidino groups areconventionally protecting groups in the field of amino acid chemistrysuch as carbobenzoxy, methylbenzyloxycarbonyl, butoxycarbonyl, tosyl,benzyl, methyl, ethyl, acetyl, formyl, nitro and the like.

Preferred compounds of the present invention are the compounds offormula(I) wherein R¹ is hydrogen or alkali metal, R² is alkyl having3-4 carbon atoms, R³ is hydrogen, and R⁴ is alkyl having 1-10 carbonatoms. More preferred compounds of the present invention are thecompounds of formula(I) wherein R¹ is hydrogen, R² is alkyl having 4carbon atoms, and R⁴ is isoamyl.

A compound of formula(I) may be prepared, for example, as follows: Anepoxysuccinic acid monoester of the formula ##STR4## wherein R⁷ ishydrogen or alkali metal, and

R⁸ is alkyl having 1-2 carbon atoms, cycloalkyl having 5-6 carbon atomsor benzyl, may be treated with a chlorinating agent such as oxalylchloride, thionyl chloride or the like to give the corresponding acidchloride. To the acid chloride, an amino acid compounds of the formula##STR5## wherein R², R³ and R⁴ are as defined above, may be addeddropwise under ice cooling to give the compound of formula(I) wherein R¹is R⁸. In this amidation, the amino acid compound may be accompanied bya base such as triethylamine, pyridine, methylmorphorine or the like.When the compound of formula(III) is employed directly in the form of anacid-addition salt, it may be provided for the reaction after removeingthe acid with a base such as an alkali hydroxide, triethylamine,pyridine or methylmorpholine, alternatively it may be allowed to reactin the presence of the base mentioned above.

The compound of formula(II) wherein R⁷ is hydrogen also can be directlyconverted to the compound of formula(I) wherein R¹ is R⁸ withoutchlorinating. In this case, the compound of formula(II) wherein R⁷ ishydrogen may be reacted with the compound of formula(III) in thepresence of a condensing agent such as N,N'-dicyclohexylcarbodiimide,1-ethyl-3(3-dimethylaminopropyl)carbodiimide (hereinafter abbreviated asW.S.C.) or the like. Also preferred in this reaction is the addition ofan N-hydroxy compound such as N-hydroxysuccinimide,1-hydroxybenzotriazole or the like.

Alternatively, the compound of formula(I) wherein R¹ is R⁸ may beprepared by the amidation of the compound of the formula ##STR6##wherein R² and R⁸ are as defined above, with an amine of the formula##STR7## wherein R³ and R⁴ are as defined above. This amidation can becarried out by following the same procedure as that of the reaction ofthe compound of formula(II) wherein R⁷ is hydrogen with the compound offormula(III).

Also alternatively, the compound of formula(I) wherein R¹ is R⁸ may beprepared by ester-exchange reaction of the compound of formula(I),wherein R¹ is another ester within the scope of R⁸ with an alcohol,which can form the desired ester group of R⁸, such as methanol, ethanol,cyclopentanol, cyclohexanol, or benzyl alcohol, in the presence of acatalyst such as sulfuric acid, an alkali metal alcoholate or an alkalihydroxide such as sodium hydroxide, potassium hydroxide or the like.

The compound of formula(I) wherein R¹ is alkali metal may be prepared bya process which comprises treating the compound of formula(I) wherein R¹is R⁸ with an alkali hydroxide such as sodium hydroxide, potassiumhydroxide or the like, and then, if necessary, following by addition ofan organic solvent such as ethanol, acetone, ethyl ether, petroleumether or the like.

The compound of formula(I) wherein R¹ is hydrogen may be prepared by aprocess which comprises acidifying the compound of formula(I) wherein R¹is alkali metal with an inorganic acid such as hydrochloric acid orsulfuric acid, or an organic acid such as formic acid or acetic acid,and then, extracting with a suitable organic solvent such as ethylacetate, ethyl ether, benzene or chloroform.

In case where the compound of formula(I) has amino protected withcarbobenzoxy, guanidino protected with nitro, or carboxy protected withbenzyl, such protecting groups may be removed by catalytic reductionusing palladium-on-charcoal or palladium black.

The compounds of formulae(II) and (IV) can be prepared by the method asdescribed in German Patent Application Laying Open No. P 28 09 036 or bythat with some modification.

The compound of formula(III) can be prepared as follows: The compound ofthe formula ##STR8## wherein R² is as defined above and R⁹ is aprotecting group, may be reacted with the compound of formula(V),followed by removal of the protecting group to give the desiredcompound. Examples of the protecting group are conventional groups inthe field of peptide synthesis such as t-butoxycarbonyl, carbobenzoxy ormethylbenzyloxycarbonyl. The amidation of the compound of formula(VI)with the compound of formula(V) can be carried out by following the sameprocedure as that of the reaction of the compound of formula(II) whereinR⁷ is hydrogen with the compound of formula(III). Removal of theprotecting group can be carried out according to the conventional mannerin the field of peptide chemistry.

The compounds of formulae(V) and (VI) are to a large extent commerciallyavailable.

The compounds of the present invention have superior inhibitory activityto CANP which exists in excess in muscle of muscular dystrophy mammals,and superior absorption and distribution in tissues after administrationto mammals as compared with the epoxysuccinic acid derivatives of GermanPatent Application Laying Open No. P 28 09 036 and Chemical Abstracts,87, 68129a (1977). Their muscular dystrophy inhibitory activity wasassayed by the method of Ishiura et al, [J. of Biochem., 84, 225(1978)]using CANP prepared from a muscle of hereditary muscular dystrophychicken, and the resulting value for 50% inhibition in the molar ratiosfor the enzyme expressed as ID₅₀ (mole/mole) is shown in Table 1.

The compounds of the present invention are better absorbed by thesubcutaneous route in mammals such as rats or rabbits, as compared withthe epoxysuccinic acid derivatives of the German Patent Laid OpenApplication described above and Chemical Abstracts, 87, 68129a (1977).To determine absorption, these compounds were administeredsubcutaneously to rat at a dose of 50 mg/kg, and the concentration ofthe test compound in rat plasma at an hour after the administration wasshown in Table 1.

                  TABLE 1                                                         ______________________________________                                                CANP Inhibitory Activity                                                                       Concentration in                                     Compound                                                                              ID.sub.50 (mole/mole)                                                                          rat plasma (μg/ml)                                ______________________________________                                        12      65               1.3                                                  15      35               20                                                   16      90               12                                                   19      23               1.5                                                  30      100              2.0                                                  36      200              1.8                                                  42      120              1.1                                                  43      100              7.0                                                  45      64               15                                                   A       5,400            below 1.0                                            B       410              "                                                    C       580              below 1.0                                            D       574              "                                                    E       4,600            "                                                    ______________________________________                                    

(Note)

Number in compound column of Table 1 means a compound which is preparedin the following Example attached the example number corresponding tosaid number. Also, symbols A-E in compound column of Table 1 mean thefollowing known compounds:

A: Ethyl hydrogen epoxysuccinate

B: Benzyl hydrogen epoxysuccinate

C: N-(3-ethoxy-carbonyloxirane-2-carbonyl)-L-leucine benzyl ester

D: N-(3-carboxyoxirane-2-carbonyl)-L-phenylalanine benzyl ester

E: N-(3-carboxyoxirane-2-carbonyl)-L-leucine

The compounds of the present invention also inhibit effectively andspecifically thiol proteases such as papain, bromelains and some kindsof cathepsin in which some sulfhydryl groups are essential for activity.On the other hand, they have neither inhibitory activity againstproteolysis of casein by trypsin, chymotrypsin, pepsin, an acid proteaseof Paecilomyces varioti or Nagase (trademark of Nagase Industry),against esteolysis of benzoylarginine ethyl ester by kallikrein noragainst fibrinolysis by human plasmin.

Papain inhibitory activity of the compounds of the present invention wasassayed by the method of K. Hanada et al, [Argric. Biol. Chem., 42, No.3, 523(1978)] using papain (80 μg/ml, Sigma Chem. Co., 2×cry.). Theamounts of inhibitor for 50% inhibition was expressed as ID₅₀ and shownin Table 2.

                  TABLE 2                                                         ______________________________________                                                ID.sub.50         ID.sub.50     ID.sub.50                             Compound                                                                              (μg) Compound  (μg)                                                                             Compound                                                                              (μg)                               ______________________________________                                        1       0.439   10        0.510 19      0.123                                 2       0.227   11        0.184 20      0.255                                 3       1.10    12        0.260 21      0.169                                 4       0.417   13        0.255 22      8.28                                  5       0.284   14        0.187 23      0.221                                 6       0.410   15        0.112 24      0.219                                 7       0.410   16        0.123 25      0.223                                 8       0.446   17        0.255 26      0.139                                 9       0.313   18        29.07 27      0.216                                 28      0.156   35        0.212 42      0.595                                 29      0.35    36        0.595 43      0.195                                 30      0.391   37        2.50  44      0.250                                 31      0.375   38        0.305 45      0.236                                 32      0.227   39        0.408 46      0.105                                 33      0.255   40        0.481 47      0.260                                 34      0.298   41        0.272 48      0.215                                 ______________________________________                                    

(Note)

Number in compound column of Table 2 is as defined in Table 1.

The compounds of the present invention show no side-effect such asacceleration of vascular permeability and are superior to E-64 and itsintermediates in this regard.

The pharmaceutical forms contemplated by the present invention includepharmaceutical compositions suited for oral, parenteral, and rectal use,e.g., tablets, powder packets, cachets, dragees, capsules, solutions,suspensions, sterile injectable forms, suppositories, bougies, and thelike. The carrier employed may be, for example, either a solid orliquid. Examples of solid carriers are lactose, terra alba, sucrose,talc, gelatin, agar, pectin, acacia, magnesium stearate, stearic acidand the like. Examples of liquid carriers are syrup, peanut oil, oliveoil, water and the like. Similarly, the carrier or diluent can includeany time delay material well known to the art, such as glycerylmonostearate or glyceryl distearate alone or with a wax.

The compounds of the present invention can be used to inhibit CANP whichexists in excess in muscle of muscular dytrophy mammals by theadministration of about 5 to 400 mg/kg/day in single or two to fourdivided doses in oral or injectable preparations as described above.

The compounds of the present invention are of extremely low toxicity.That is, they show hardly any oral acute toxicity on mice at the dosagesless than 2 g/day of body weight. Moreover, no side-effect is observedafter administration of 1 g/kg/day orally for 30 days to laboratoryanimals.

The following examples show representative compounds encompassed withinthe scope of the present invention and the manner in which suchcompounds are prepared. However, it is to be understood that theexamples are for purposes of illustration only.

EXAMPLE 1

In 30 ml of tetrahydrofuran were dissolved 1.09 g ofN-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucine, 0.43 g ofhexylamine, 0.60 g of 1-hydroxybenzotriazole and 0.44 g ofN-methylmorpholine. To the solution was added little by little 0.84 g ofW.S.C. hydrochloride under ice-cooling and stirring. The mixture wasstirred for 2 hours keeping that temperature and another an hour at roomtemperature. The solution was concentrated and to the resulting residuewere added 80 ml of water and 80 ml of ethyl acetate. The mixture wasshaken and the ethyl acetate layer was separated. The aqueous layer wasfurther extracted twice with ethyl acetate. The extracts were combinedwith the said ethyl acetate layer, washed successively with a 10%aqueous hydrochloric acid solution, a saturated sodium bicarbonatesolution and a saturated sodium chloride solution, dried over magnesiumsulfate and concentrated to dryness. The resulting residue was purifiedby silica gel column chromatography (chloroform:acetone=40:1) andcrystallized from chloroform-ethyl ether to give 0.97 g ofN-[N'-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucyl]cyclohexylamine,m.p. 168°-169° C.

EXAMPLE 2

Following the procedure of Example 1 and using 1.09 g ofN-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucine and 0.69 g ofn-decylamine, there was obtained 1.0 g ofN-[N'-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucyl]-n-decylamineas viscous oil.

IRν_(max) ^(neat) (cm⁻¹): 3270 (amine), 1750 (ester), 1635, 1560(amide), 897 (epoxy).

NMR (60 MHz, CDCl₃) δ=0.92 (d, J=5 Hz, 6H), 1.25 (b.s., 22H), 1.6 (b.s.,3H), 3.18 (m, 2H), 3.42 (d, J=2 Hz, 0.5H), 3.48 (d, J=2 Hz, 0.5H), 3.63(d, J=2 Hz, 1H), 4.19 (q, J=7 Hz, 2H), 4.0-4.7 (m, 1H), 6.2-6.6 (br.,1H), 6.6-7.1 (br., 1H).

Mass m/e=412 (M⁺).

EXAMPLE 3

Following the procedure of Example 1 and using 1.09 g ofN-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucine and 0.31 g ofpyrrolidine, there was obtained 0.89 g of oilyN-[N'-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucyl]pyrrolidine.

IRν_(max) ^(neat) (cm⁻¹): 3250 (amine), 1740 (ester, 1680, 1620, 1540(amide), 895 (epoxy).

NMR (60 MHx, CDCl₃) δ=0.94 (d, J=5 Hz, 3H), 0.96 (d, J=5 Hz, 3H), 1.28(t, J=7 Hz, 3H), 1.20-2.40 (m, 7H), 3.10-3.60 (m, 5H), 3.69 (d, J=2 Hz,1H), 4.20 (q, J=7 Hz, 2H), 4.50-5.00 (m, 1H), 6.80-7.50 (br., 1H).

Mass m/e=326 (M⁺).

EXAMPLE 4

Following the procedure of Example 1 and using 1.09 g ofN-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucine and 0.37 g ofpiperidine, there was obtained 0.7 g of oilyN-[N'-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucyl]piperidine.

IRν_(max) ^(neat) (cm⁻¹): 3250 (amine), 1735 (ester), 1620, 1540(amide), 895 (epoxy)

NMR (60 MHz, CDCl₃) δ=0.93 (t, J=5 Hz, 6H), 1.29 (t, J=7 Hz, 3H), 1.60(b.s., 9H), 3.45 (b.s., 4H), 4.17 (q, J=7 Hz, 2H), 4.65-5.2 (m, 1H),6.8-7.4 (br.; 1H)

Mess m/e=340 M⁺)

EXAMPLES 5-9

Following the procedure of Example 1 and using the correspondingstarting materials, there were obtained the compounds of formula(I) inTable 3.

                                      TABLE 3                                     __________________________________________________________________________     ##STR9##                   (I)                                                Example                                                                            R.sup.1                                                                             R.sup.2                                                                                ##STR10##    m.p. (°C.)                           __________________________________________________________________________    5    CH.sub.3 CH.sub.2                                                                    ##STR11##                                                                              ##STR12##   148-149                                      6    "     "                                                                                       ##STR13##   146.5-147.5                                  7    "     "                                                                                       ##STR14##   108-110                                      8    "     "                                                                                       ##STR15##   131-132                                      9    "     "        NHCH.sub.2 CH.sub.2 CH.sub.3                                                               122-124                                      __________________________________________________________________________

EXAMPLE 10

In 10 ml of tetrahydrofuran were dissolved 0.36 g ofDL-trans-benzylhydrogenoxirane-2,3-dicarboxylate, 0.35 g ofN-L-leucyl-N-methylaniline, 0.23 g of 1-hydroxybenzotriazole and 0.17 gof N-methylmorpholine. To the solution was added little by little 0.33 gof W.S.C. hydrochloride with ice-cooling and stirring. The mixture wasstirred for 2 hours keeping that temperature and another an hour at roomtemperature. The solution was concentrated to distil off almosttetrahydrofuran and the resulting residue was suspended in 50 ml ofwater and extracted three times with 50 ml of ethyl acetate each. Theextracts were combined, washed successively with a 5% aqueoushydrochloric acid solution, a saturated sodium bicarbonate solution anda saturated aqueous sodium chloride solution, dried and concentrated todryness. The resulting oil was purified by silica gel columnchromatography (chloroform:acetone=40:1) to give 0.57 g of oilyN-[N'-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl]-N-methylaniline.

IRν_(max) ^(neat) (cm⁻¹): 3265 (amine), 1753 (ester), 1650, 1530(amide), 893 (epoxy).

NMR (60 MHz, CDCl₃) δ=0.38 (d, J=5 Hz, 3H), 0.70 (d, J=5 Hz, 3H),1.10-1.80 (m, 3H), 3.16 (d, J=2 Hz, 0.5H), 3.18 (s, 3H), 3.42 (d, J=2Hz, 0.5H), 3.58 (d, J=2 Hz, 1H), 4.20-4.80 (m, 1H), 4.95 (s, 1H), 5.08(s, 1H), 6.40-6.90 (br., 1H), 6.90-7.70 (m, 10H).

Mass m/e=424 (M⁺).

EXAMPLE 11

Following the procedure of Example 10 and using 1.4 g ofDL-trans-benzylhydrogenoxirane-2,3-dicarboxylate and 0.99 g ofN-L-leucyldimethylamine, there was obtained 1.68 g of oilyN-[N'-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl]dimethylamine.

IRν_(max) ^(neat) (cm⁻¹): 3260 (amine), 1753 (ester), 1690, 1630, 1540(amide), 895 (epoxy).

NMR (60 MHz, CDCl₃) δ=0.92 (d, J=5 Hz, 3H), 0.99 (d, J=5 Hz, 3H),1.10-1.80 (m, 3H), 2.90 (s, 3H), 3.04 (s, 3H), 3.49 (d, J=2 Hz, 0.5H),3.56 (d, J=2 Hz, 0.5H), 3.66 (d, 2 Hz, 1H), 4.70-5.00 (m, 1H), 5.14 (s,2H), 6.50-7.10 (br., 1H), 7.27 (s, 5H).

Mass m/e=362 (M⁺).

EXAMPLE 12

Following the procedure of Example 10 and using 2.2 g ofDL-trans-benzylhydrogenoxirane-2,3-dicarboxylate and 2.3 g ofN-L-isoleucyl-N-methylbenzylamine, there was obtained 2.8 g of oilyN-[N'-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-isoleucyl]-N-methylbenzylamine.

IRν_(max) ^(neat) (cm⁻¹): 3255 (amine), 1750 (ester), 1685, 1630, 1535(amide), 897 (epoxy).

NMR (60 MHz, CDCl₃). δ=0.89 (b.s., 6H), 1.0-2.0 (m, 3H), 2.95 (s, 3H),3.47 (d, =J=2 Hz, 0.5H), 3.52 (d, J=2 Hz, 0.5H), 3.68 (d, J=2 Hz, 1H),4.1-4.95 (m, 3H), 5.10 (s, 2H), 6.5-7.4 (m, 11H).

Mass m/e=438 (M⁺).

EXAMPLE 13

0.2 g ofN-[N'-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucyl]cyclohexylaminewas dissolved in a mixture of 1 ml of cyclohexylalcohol and 5 ml ofbenzene. After adding one drop of conc. sulfuric acid, the solution wasrefluxed for 15 hours. After reflux, 50 ml of benzene was added to thesolution. The mixture was washed successively with a saturated aqueoussodium bicarbonate solution and a saturated aqueous sodium chloridesolution and concentrated to dryness. The resulting residue was purifiedby silica gel column chromatography (chloroform:acetone=70:1) andcrystallized from chloroform-ethyl ether to give 0.16 g ofN-[N'-(DL-3-trans-cyclohexyloxycarbonyloxirane-2-carbonyl)-L-leucyl]cyclohexylamine,m.p. 185.5°-186.5° C.

EXAMPLE 14

Following the procedure of Example 13 and using 0.2 g ofN-[N'-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucyl]cyclopentylamineand 1 ml of cyclopentylalcohol, there was obtained 0.15 g ofN-[N'-(DL-3-trans-cyclopentyloxycarbonyl)-L-leucyl]cyclopentylamine,m.p. 158°-160° C.

EXAMPLE 15

0.34 g ofN-[N'-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucyl]isopropylaminewas dissolved in 5 ml of ethanol, followed by adding 0.056 g ofpotassium hydroxide in 2 ml of ethanol under ice-cooling and stirring.The mixture was stirred for 2 hours under ice-cooling. To the mixturewas added 50 ml of ethyl ether and the produced precipitates werecollected by filtration to afford 0.23 g ofN-[N'-(DL-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl]isopropylaminepotassium salt, m.p. 174°-175° C. (with decomposition).

EXAMPLE 16

Following the procedure of Example 15 and using 0.37 g ofN-[N'-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-leucyl]phenethylamineand 0.056 g of potassium hydroxide, there was obtained 0.23 g ofN-[N'-(DL-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl]phenethylaminepotassium salt, m.p. 163°-165° C. (with decomposition).

EXAMPLE 17

To 30 ml of a benzene solution containing 1.5 g of L-leucyl-L-leucinebenzyl ester and 0.55 g of triethylamine was added dropwise 20 ml of abenzene solution containing 1.2 g of epoxysuccinic acid monobenzyl esterchloride over 30 minutes under ice-cooling and stirring. The mixture wasstirred for 2 hours under ice-cooling and another an hour at roomtemperature. The produced precipitates were filtered off. The resultingfiltrate was washed successively with a 5% aqueous hydrochloric acidsolution, a saturated sodium bicarbonate solution and a saturatedaqueous sodium chloride solution, dried over magnesium sulfate andconcentrated to dryness. The resulting residue was purified by silicagel column chromatography (ethyl acetate:n-hexane=1:2) and crystallizedfrom ethyl ether-petroleum ether to give 1.8 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-L-leucinebenzyl ester, m.p. 91°-93° C.

EXAMPLE 18

Following the procedure of Example 17 and using 0.46 g ofL-phenylalanyl-L-phenylalanine methyl ester and 0.26 g of epoxysuccinicacid monoethyl ester chloride, there was obtained 0.27 g ofN-(DL-3-trans-ethoxycarbonyloxirane-2-carbonyl-L-phenylalanyl-L-phenylalaninemethyl ester, m.p. 142°-143° C.

EXAMPLE 19

Following the procedure of Example 17 and using 1.3 g ofL-leucyl-L-proline methyl ester and 1.4 g of epoxysuccinic acidmonobenzyl ester chloride, there was obtained 1.32 g of oilyN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-L-prolinemethyl ester.

IR_(max) ^(neat) (cm⁻¹): 3300 (amine), 1750 (ester), 1690, 1630, 1550(amide), 900 (epoxy).

NMR (60 MHz, CDCl₃) δ=0.96 (d, J=5 Hz, 6H), 1.10-2.40 (m, 7H), 3.30-3.90(m, 4H), 3.64 (s3H), 4.10-4.90 (m, 2H), 5.11 (s, 2H), 6.30-7.00 (br.,1H), 7.27 (s, 5H).

Mass m/e=446 (M⁺).

EXAMPLE 20

To a solution of 1.5 g ofDL-trans-benzylhydrogenoxirane-2,3-dicarboxylate, 1.75 g ofL-leucine-L-glutamic acid dimethyl ester, 0.88 g of1-hydroxybenzotriazole and 0.66 g of N-methylmorpholine in 50 ml oftetrahydrofuran was added little by little 1.24 g of W.S.C.hydrochloride under ice-cooling and stirring. The mixture was stirredfor an hour under ice-cooling and for another 2 hours at roomtemperature. Tetrahydrofuran was almost distilled off under reducedpressure. 80 ml of water was added to the resulting residue and themixture was extracted twice with 80 ml of ethyl acetate each. The ethylacetate extracts were combined, washed successively with a 5% aqueoushydrochloric acid solution, a saturated sodium bicarbonate solution anda saturated aqueous sodium chloride, dried over magnesium sulfate andconcentrated to dryness. The resulting residue was purified by silicagel column chromatography (chloroform:acetone=70:1) and crystallizedfrom chloroformethyl ether to give 1.65 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-L-gluamicacid dimethyl ester, m.p. 126°-128° C.

EXAMPLE 21

Following the procedure of Example 20 and using 1.3 g ofDL-trans-benzylhydrogenoxirane-2,3-dicarboxylate and 1.3 g ofL-leucyl-L-isoleucine methyl ester, there was obtained 2.2 g of oilyN-(DL-3 trans-benzyloxycarbonyloxirane-2-carbonyl)L-leucyl-L-isoleucinemethyl ester.

IRν_(max) ^(neat) (cm⁻¹): 3300 (amine), 1740 (ester), 1660, 1550(amide), 900 (epoxy).

NMR (60 MHz, CDCl₃) δ=0.92 (b.s., 12H), 1.3-2.0 (m, 6H), 3.45 (d, J=2Hz, 0.5H), 3.49 (d, J=2 Hz, 0.5H), 3.63 (d, J=2 Hz, 1H), 3.66 (s, 3H),4.2-4.7 (m, 2H), 5.13 (s, 2H), 6.3-6.7 (br., 2H), 7.26 (s, 5H).

Mass m/e=462 (M⁺)

EXAMPLE 22

Following the procedure of Example 20 and using 0.96 g ofDL-trans-benzylhydrogenoxirane-2,3-dicarboxylate and 1.12 g ofD-leucyl-L-leucine methyl ester, there was obtained 1.3 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-D-leucyl-L-leucinemethyl ester as viscous oil.

IRν_(max) ^(neat) (cm⁻¹): 3260 (amine), 1740 (ester), 1670, 1645, 1553(amide), 897 (epoxy).

NMR (60 MHz, CDCl₃) δ=0.91 (d, J=5 Hz, 12H), 1.2-2.0 (m, 6H), 3.46 (d,J=2 Hz, 0.5H), 3.59 (s, 3H), 3.60 (d, J=2 Hz, 0.5H), 3.66 (d, J=2 Hz,1H), 4.20-4.90 (m, 2H), 5.12 (s, 2H), 6.30-6.70 (br., 2H), 7.24 (s, 5H).

Mass m/e=462 (M⁺).

EXAMPLE 23

Following the procedure of Example 20 and using 0.95 g ofDL-trans-benzylhydrogenoxirane-2,3-dicarboxylate and 1.1 g ofL-leucyl-D-leucine methyl ester, there was obtained 1.38 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-D-leucinemethyl ester as viscous oil.

IRν_(max) ^(neat) (cm⁻¹): 3270 (amine), 1740 (ester), 1670, 1645, 1545(amide), 895 (epoxy).

NMR (60 MHz, CDCl₃) δ=0.90 (d, J=5 Hz, 6H), 1.30-1.90 (m, 3H), 3.45 (d,J=2 Hz, 0.5H), 3.55-3.70 (m, 1.5H), 3.62 (s, 3H), 4.10-4.80 (m, 2H),5.12 (s, 2H), 6.30-6.70 (br., 2H), 7.22 (s, 5H).

Mass m/e=462 (M⁺).

EXAMPLE 24

0.5 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-D-leucinemethyl ester obtained in Example 23 was adsorbed by cilica gel columnchromatography (1.5 cm×40 cm, chloroform). 5 g of the silica gel wasplaced in each test tube and treated with thin layer chromatography(silica gel, chloroform:acetone=40:1) to obtain two fractions, one ofwhich contained the compound having higher Rf value and the othercontained the compound having lower Rf value.

The fraction containing the compound having higher Rf value wasconcentrated and the resulting residue was crystallized from ethylether-petroleum ether to obtain 0.15 g ofN-(D-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-D-leucinemethyl ester, m.p. 95°-97° C., [α]_(D) ²⁸ =-51.1 (c=1, ethanol).

EXAMPLE 25

The fraction containing the compound having lower Rf value, which wasobtained from the silica gel in Example 24, was concentrated and theresulting residue was crystallized from ethyl ether-petroleum ether togive 0.14 g ofN-(L-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-D-leucinemethyl ester, m.p. 72°-73° C., [α]_(D) ²⁸ =+44.0 (c=1, ethanol).

EXAMPLES 26-42

Following the procedure of Example 20 and using the correspondingstarting materials, there were obtained the compounds of formula (I) inTable 4.

                                      TABLE 4                                     __________________________________________________________________________     ##STR16##                  (I)                                                Example                                                                            R.sup.1    R.sup.2                                                                                 ##STR17##                                                                              m.p. (°C.)                         __________________________________________________________________________    26                                                                                  ##STR18##                                                                             ##STR19##                                                                             Arg(NO.sub.2)OCH.sub.3                                                                     184˜185                              27   "       "        MetOCH.sub.3 141˜142                              28   CH.sub.3                                                                              "        "            130˜132                              29                                                                                  ##STR20##                                                                            "        ThrOCH.sub.3 102˜103                              30   "       "                                                                                       ##STR21##   146˜149                              31   "       "        PheOCH.sub.2 H.sub.5                                                                       118˜120                              32   "       "        LeuOCH.sub. 3                                                                              120˜122                              33   "       "                                                                             (D-isomer)                                                                             LeuOCH.sub.3 106˜108                                                    (D-isomer)                                              34   "       "        LeuNH.sub.2  186˜187                              35   C.sub.2 H.sub.5                                                                       "                                                                                       ##STR22##   109.5˜110.5                          36                                                                                  ##STR23##                                                                             ##STR24##                                                                             LeuOCH.sub.3 147˜148                              37   "       "        PheOCH.sub.3 113˜114                              38   "                                                                                      ##STR25##                                                                             TrpOCH.sub.3 173˜175                              39                                                                                  ##STR26##                                                                             ##STR27##                                                                             TyrOCH.sub.3 113˜115                              40   "       "        GlyOC.sub.2 H.sub.5                                                                        167.5˜168.5                          41   "       "        ValOCH.sub.3 153˜154                              42   "                                                                                      ##STR28##                                                                             AlaOCH.sub.3 192˜195                              __________________________________________________________________________

(Note)

In the above Table Arg(NO₂) means N^(G) -nitro-L-arginyl group, Metmethionyl group, Thr threonyl group, Orn(z) δ-carbobenzoxy-L-ornithylgroup, Phe phenylalanyl group, Leu Leucyl group, Trp trypsinyl group,Tyr tyroxinyl group, Gly glycyl group, Val valyl group, Ala alanylgroup, respectively and the compounds other than those described asD-isomer are L-isomer.

EXAMPLE 43

In a mixture of 8 ml of methanol, 2 ml of acetic acid and 1 ml of waterwas dissolved 0.1 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-N^(G)-nitro-L-arginine methyl ester obtained in Example 26. After addition of50 mg of 5% palladium-on-charcoal, the mixture was stirred for 4 hoursat room temperature in a weak stream of hydrogen. The reaction mixturewas filtered and the filtrate was concentrated. The resulting residuewas treated by column chromatography on Sephadex-LH20 (methanol) andcrystallized from methanol-chloroform to obtain 0.068 g ofN-(DL-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl-L-arginine methylester, m.p. 160°-165° C. (with decomposition).

EXAMPLE 44

Following the procedure of Example 43 and using 0.31 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-δ-carbobenzoxy-L-ornithinebenzyl ester obtained in Example 30 and crystalling the resultingproduct from water-acetone, there was obtained 0.1 g ofN-(DL-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl-L-ornithine, m.p.187°-188° C.

EXAMPLE 45

In 20 ml of ethanol was dissolved 0.5 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-L-leucinebenzyl ester obtained in Example 17. After addition of 0.2 g of 5%palladium-one-charcoal, the mixture was stirred for 6 hours at roomtemperature in a weak stream of hydrogen. The reaction mixture wasfiltered and the filtrate was concentrated. The resulting residue wascrystallized from ethanol-ethyl ether to afford 0.32 g ofN-(DL-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl-L-leucine, m.p.121°-123° C.

EXAMPLE 46

Following the procedure of Example 45 and using 0.21 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-L-prolinemethyl ester obtained in Example 19 and purifying the resultingconcentrate by silica gel column chromatography(chloroform:methanol=20:1), there was obtained 0.095 g of oilyN-(DL-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl-L-proline methylester.

IRν_(max) ^(neat) (cm⁻¹): 3250 (amine), 1740 (ester), 1620, 1560(amide), 900 (epoxy).

NMR (60 MHz, CDCl₃) δ=0.96 (d, J=5 Hz, 6H), 1.20-2.60 (m, 7H), 3.40-3.90(m, 4H), 3.68 (s, 3H), 4.10-5.00 (m, 2H), 7.60-8.00 (br., 1H), 8.80-9.30(br., 1H).

EXAMPLE 47

Following the procedure of Example 46 and using 0.188 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-L-glutamicacid dimethyl ester obtained in Example 20, there was obtained 0.1 g. ofoily N-(DL-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl-L-glutamic aciddimethyl ester.

IRν_(max) ^(neat) (cm⁻¹): 3280 (amine), 1730 (ester), 1650, 1550(amide), 900 (epoxy).

NMR (60 MHz, CDCl₃) δ=0.92 (d, J=5 Hz, 6H), 1.20-2.70 (m, 7H), 3.57 (s,3H), 3.63 (s, 3H), 3.45-3.70 (m, 2H), 4.10-4.80 (m, 2H), 5.90-6.50 (m,2H), 7.10-7.70 (br., 1H)

EXAMPLE 48

In benzyl alcohol was dissolved 0.54 g ofN-(DL-3-trans-benzyloxycarbonyloxirane-2-carbonyl)-L-leucyl-L-leucinebenzyl ester obtained in Example 17. To the solution was added dropwise5 ml of a benzyl alcohol solution containing 0.56 g of potassiumhydroxide under ice-cooling and stirring. The mixture was stirred for 2hours under ice-cooling. Petroleum ether was added to the reactionmixture and the produced precipitates were collected on a filter. Theywere dissolved in 10 ml of a 5% aqueous hydrochloric acid solution andextracted twice with 10 ml of ethyl acetate each. The extracts werecombined, washed with a saturated sodium chloride solution andconcentrated. The resulting residue was purified by silica gel columnchromatography (chloroform:methanol=4:1) and crystallized fromchloroform-n-hexane to obtain 0.23 g ofN-(DL-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl-L-leucine benzylester, m.p. 103°-104° C.

What is claimed is:
 1. An epoxysuccinic acid derivative of the formula##STR29## wherein R¹ is hydrogen, alkali metal, alkyl having 1-2 carbonatoms, cycloalkyl having 5-6 carbon atoms or benzyl,R² is a branchedchain alkyl group having 3-4 carbon atoms or benzyl, R³ is hydrogen ormethyl, and R⁴ is alkyl having 1-10 carbon atoms, phenyl benzyl,phenethyl, or cycloalkyl having 3-6 carbon atoms, or R³ and R⁴ takentogether with the nitrogen atom to which they are attached form apyrrolidino heterocyclic ring, or said heterocyclic ring substitutedwith a protected carboxy.
 2. A compound according to claim 1 wherein R¹is hydrogen or alkali metal, R² is a branched chain alkyl group having3-4 carbon atoms, R³ is hydrogen and R⁴ is alkyl having 1-10 carbonatoms.
 3. A compound according to claim 2 wherein R¹ is hydrogen, R² isa branched chain alkyl group having 4 carbon atoms, R³ is hydrogen andR⁴ is isoamyl.